Slow nitrogen releasing fertilizers and methods of making the same

ABSTRACT

Wax and preferably, cork are removed from Douglas fir bark, and the residue is blended with water soluble nutrient fertilizer materials and pressed into pellets. The pellets are excellent fertilizers and release nitrogen into soil to which they are applied at optimum rates for long periods of time.

United' States Patent 1 Troeino 1 1 stow N1TRQ1NRELEASlNG FERTILIZERS'AND METHODS OF MAKING THESAME Inventor: LFt'anli Assignee:

Filed:

Appl. No.:

[ Irdcirio, Eugene, Oreg. 73.]

Bohemia lnc., E ugene, Qreg. ,1 1974 U.S. C1. 71/23; 71/28; 71/29; 71/30; 71/33; 71/58; 71/61 Int. Cl. C051 11/00; COSC 9/00; COSB 15/00; C056 1/02 Field 01 Search 71/23, 24, 28, 30, 61. 71/64 F, 64 G, 33, 58

[56] Relerencea Clted UNITED STATES PATENTS 2,255,027 9/1941 Keenan et a1 71/30 1 Dec. 30, 1975 13,239,329 3/1966 Burgon 71/23 3,645,714 2/1972 Hcming et a1. 71/23 3,781,187 12/1973 Trocino 162/93 Primary Examiner-Charles N. Hart Assistant Examiner-Ferris H. Lander Attorney, Agent, or Firm-Klarquist, Sparkman, Campbell, Leigh, Hall & Whinston [57] ABSTRACT Wax and preferably, cork are removed from Douglas fir bark, and the residue is blended with water soluble nutrient fertilizer materials and pressed into pellets. The pellets are excellent fertilizers and release nitrogen into soil to which they are applied at optimum rates for long periods of time.

13 Claims, 2 Drawlng Flgures BARK AT 3'8 71 HOPPER 1 M01 STUR E 200 MESH SCREEN wTANK H EATING COIL GRIND BARK IN HAMMERMILL HAVING 3/I6 IN. ROUND HOLE SCREEN EXTRACT WAX WITH HOT NEUTRAL ORGANIC SOLVENT FIG. I

HEAT TO DESOLVENTIZE RESIDUE & EXPAND CORK FRACTION M ECHANICALLY CLA SSIFY DESOLVENTIZED RESIDUE TO REMOVE CORK BLEND BARK RESIDUE RI ENT AND NUT FERTILIZER PELLETIZE BLENDED BARK AND NUTRIENT FERTILIZER FIG. 2

HOP PER 1 AT 3-8 MOISTURE BARK 200 MESH SCREEN 'uTANK HEATING COIL CIRCULATE SOLVENT AT IE OE FOR 2 HOUR? A PUMP SLOW NITROGEN RETJEASING FERTILIZERS AND METHODS'OF MAKING THE SAME BACKGROUND .THE- INVENTION This invention relates .to 'slow nitrogen releasing fertilizers and methodsofm'aking the same.

Heming et al. US. Pat. No. 3,645,714 disclosed that certain barks, namely; barks of-l hemlock, balsam, spruce, pine and redwood, ;when-m ixed with water soluble nutrient fertilizer materials and pelietized, formed materials which broke down sufficiently well in water to be useful as" fertilizers. This patent 'aiso disclosed that unprocessed Douglas fir bark mixed with the same water soluble nutrient fertilizer materials showed such poor ability to break down in water that it was wholly unsatisfactoryfor use. While tests subsequent to this patents issuance indicate that unprocessed Douglas fir bark, when mixed with urea and peiletized, works satisfactorily to release nitrogen slowly for short periods of two to three months, thereafter release falls off too fast to be satisfactory for use as a fertilizer where the nitrogen must be released for several months longer.

it is thus an object of the present invention to provide new and improved slow nitrogen releasing fertilizers and methods of making the same.

Another object of the invention is to provide slow nitrogen releasing fertilizers that release nitrogen immediately and maintain this release over a long period of time.

Another object of the invention is to provide slow nitrogen releasing fertilizers utilizing Douglas fir bark.

Another object of the invention is to provide a method of making slow nitrogen releasing fertilizers utilizing Douglas fir bark.

Summary of the invention l have discovered that. contrary to the teachings of the prior art, Douglas fir bark forms excellent fertilizers when wax and, preferably, cork are extracted therefrom and the residue is combined with water soluble nutrient fertilizer materials and peiletized, such fertilizon being rendered quite water-soluble and compact ible into slow disintegrating pellets.

BRIEF DESCRIPTION OF THE DRAWlNOS In the drawings:

FIG. I is a flow diagram of a method forming one embodiment of the invention; and,

FIG. 2 illustrates schematically the solvent extracting step.

DESCRlPTlON m rasrsaaso BMBODlMENTS 2 pics of suitable ones being hexane, benzene, the chlorinated hydrocarbons, naphthalenes, toluene and the like. The solvent is heated to a temperature of about 150 degrees F. and is percolated through the mixture of ground Douglas fir bark for about two-hours, the solvent being introduced to the bark in a hopper having a 200 mesh screen at its bottom and being permitted to flow therethrough by gravity. Solvent passing through the mixture is reheated to 150 degrees F. by a heating coil in a holding'tank and thereafter recirculated for the desired time. See FIG. 2. The solvent is ,circulated through the bark mixture was to remove wax an amount between about 3 and 6 percent based on the dry weight of the bark. This is approximately 60 percent of the totalwax in Douglas fir bark. Removal of this much of the wax satisfactorily prepares the bark for classification and use as a fertilizer matrix as described hereinafter. A longer period of extraction would dissolve more of the wax, but i have found this unnecessary.

After the 2-hour extracting period, the bark is drained of solvent, placed in a .dryer and heated to about 500 degrees F. for 2 to 4 minutes to drive off the solvent. The solvent can be condensed, recovered and reused. Desolventizing the bark causes the cork fraction to be expanded substantially in size, and the wax extracted residue can then be mechanically classified using standard classification equipment to achieve separation of the cork from the bast fiber and nonfibrous phloem fractions. The residue becomes the fertilizer matrix material of the present invention. l have found it desirable to remove 90-95 percent of the cork fraction, otherwise the pellet that is ultimately formed tends to break up physically. The phloem fraction may be removed or left in.

The matrix material of the residue bark then is combined with water-soluble nutrient fertilizer materials, which may be, for example, urea fines, liquid urea, ammonium nitrate, superphosphate or mixtures thereof, to form a fertilizer mixture, which, preferably, is then pelletized under pressure to condition and chemically combine the ingredients. in the process of pelletizing, heat is generated which causes a chemical reaction between the fertilizer and the residue bark. Thus the bark is used as a combination carrier and reactant.

The resulting pellets then are suitable for use as fertilizer and excellently fertilize soil. Removal of the cori achieves good structural integrity in the pellets anr consequently, good longevity. A pellet that remain! together longer, dissolves more slowly and release:

, nitrogen more slowly. Pellet size may be varied over l with round holes about 3li6th'inch in diameter. The

mixture therebyachieved is then preferably dried to between about 3 and Bpercent moisture by weight to facilitate ultimate recovery of the solvent. The mixture is then extracted with a neutral organic solvent, examwide range, for example, from if inch to l inch in diam eter and from 56 inch to over 2 inches in length, and, i1 some instances, it may be wished to use the fertilize material in unpelletized form, in which case the use might still choose to heat the material to achieve th chemical bond above noted.

EXAMPLE 1 One hundred pounds of Douglas fir bark matrix mt teriai prepared as described above by removing th wax, cork and amorphous phloem powder, was blends with SS-Vs pounds of Colliers brand agricultural grad urea in a blender. This proportion made a fertilizer wit l4 percent nitrogen. The resulting mixture was the peiletized in a California laboratory type pellet m (Model CL, Type 3). The following dies were used (d hole diameter x die depth): I

X 54 inches 4 invention both as respects the immediate release of nitrogen and the maintenance of this release over a & H4 inches sustained period of time. 3/l6 X l h g x tzi ehes 5 EXAMPLE 2 X inc esps The resulting fertilizer was'comparedwith agriculf" testsdwere run on x gd g old i p tural grade urea andurea-formaldehydefertilizers in pcpperfnmt test plots an i g. field tests to evaluate its slow nitro gen'release charac- These claslfied as chehahs i Strea O -teristics and was found demonstrablyisuperior. The li f of Slty'day he comparison tests were made bya'n independent testing onowgng mammals F". apphed on May S 3 i organization on test plots ill00 of an acre in size on a 0 9 pounds 0 mtrogen per acre t e FF' S lave] site on which was growing a uniform stand of being replicated over three plots for each fertilizer. Manhattan rye andMertoni bluegrass established in h were also three check Plots wh'ch received June 1972. The soil type was ch'ehalis-siit loam and was 5 g a g i 5 excellent. The following materials'wergappiied on Jan. a dagmufmra 22, 1973 at a rate of 200 pounds of nitrogen per acre in es ran urea e e one applicmiom g Urea-bark pellets as described in Example i;

Utewbark Pena as descdbed in this exam Urea-bark pellets made with unextracted bark, but Hercules a d, u ew omaldhyde 38%? N; a 20 otherwise the same as the pellets of Example l,i.e., Colliers brand agricultural grade urea 46% N. havmg Percent from urea; and

The materials were applied by hand and were repli- Urea-bark pellets f wnh enraged bark as m cated over three plots for each fertilizer. There were Exampl: 42 having ls.perce.m P from also three check plots which received no nitrogen. The ix?" i g i. m 50 k top one and one-half inches of leaves and stems were es were e ore an a er sampled approximately "my days for a period of fertilizing at approximately l5 day intervals. The top 6 about seven months and were enaiyzed for total nitroi of the plat were taken for the samples and such gen and nitrate nitrogen content. The turf was mechanmoulded yqung em/cs Samples were ically mowed weekly starting in April and the clippings i by an "idependem temps 'abmamry total were left on the surface. Beginning in mid-June the turf 30 Army of Plant simples pnor to was irrigated with land A inches of supplemental water femhzm? w perccm total nitrogen and no every ten days. The following test data was obtained, g'g i i :g r g i a s .nkle ed the results being the average for the three plots for each on 22 3 g: with ggi g? 2 ii; of fertilizer and for the check plots. Samples were taken pp f y d approximately in the middle of each month water applied for each setting The ollowmg test ata TN Howl "mo en coma in teem 35 was obtained, the results being the average for the mate g en cement s three plots for each fertilizer and for the three check g plots. Samples were taken on the dates indicated.

Feta-tun March A ril M .iun .i l Au ust T.N. 0 T.N. NO; p NO. T.N. NO, c NO, N. N0,

Urea-barh pellets 5.55 625 5.30 mm 4.40 960 4.40 790 3.85 650 3.70 540 3.75 570 Urea-formaldehyde 3.95 625 4.05 710 3.70 260 3.95 225 3.60 I 3.40 260 3.30 230 Agrriigitursi 4.70 s50 4.35 430 4.15 290 4.25 305 3.70 250 3.35 r50 3.40 200 0 Nil Check plots 3.00 i000 2.85 680 5.50 290 3.60 305 3J0 280 2.85 I00 2.80 H0 Total Nitrogen Content in Percent ell/73 6Ii5/73 7/1/73 7/15/73 Ell/73 Urea-extracted bark pellets 4.85 4.10 4.25 4.00 3.80 Agricultural grade urea 4.65 4.30 4.!0 3.90 3.70 Urea-unextrscted bark pellets 4.60 4.35 4.65 3.55 3.65 Urea-ammonium nitrate-extracted bark pellets 4.55 3.45 4.20 3.45 3.55 Urea-formaldehyde 4. l 5 3. l 0 3.45 3.05 3 .00 Check plots 2.00 L90 2.25 2.80 2.50

The table indicates that the plants fertilized with the extracted bark pellets made with urea exhibited the most uniform nitrogen release characteristics over the short period of time. it is believed that this is due to the fact that the presence of wax in the unextracted bark pellets inhibits the urea from'forming a chemical bond with the bark.

I claim: I. A fertilizer product comprising a matrix material of Douglas fir bark having a substantial portion of its wax and cork removed, and;-a -water-soluble nutrient fertilizer material blendedfih'to said matrix.

2. The fertilizer product of claim -.1 wherein the Douglas fir bark has about '60 percent of its wax removed.

3. The fertilizer product of claim 1 wherein the nutrient fertilizer material is urea.

4. The fertilizer product of claim 1 wherein the nutrient fertilizer material is ammonium nitrate.

5. The fertilizer product of claim 1 wherein the nutrient fertilizer material is superphosphate.

6. The fertilizer product of claim 1 wherein the mix-. ture of the matrix material and-the nutrient fertilizer material is in pellet for m.

7. The fertilizer product of claim 1 wherein the Douglas fir bark has between about 90 and 95 percent of its cork removed.

8. The method of making a fertilizer product comprising first extracting wax and then removing cork from Douglas fir bark to leave a matrix material, and thenblending a water-soluble nutrient fertilizer mate- 5 rialwith said matrix material.

9. The method of claim 8 including pelletizing the blended materials.

10. The method of claim 8 including applying pressure to the blended materials to heat and combine the materials.

11. The method of claim material is primarily urea.

12. The method of claim 8 wherein the fertilizer material is primarily ammonium nitrate.

B. The method of claim 8 wherein the fertilizer material is primarily superphosphate.

# i i i i '8 wherein the fertilizer UNITED STATES PATENT owner (IERNHCATE 0i CGRRECTION PArENT NO. 1 3, 929 ,446

DATED December 30, 19 75 iNVENTOiZ(S) Frank S. Trocino It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 6 after "inches delete --ps;

Column 3, line 75, after "nitroinsert -qen sources throughout the test period. In my exnerience no slow nitrocen release fertilizer has ever performed like urea-bark pellets made according to this-; and

Column 4 line 23, "l/Z should be --2/3--.

Signed and Salad this twenty-third Day of March 1976 [SEAL] AUESL' RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ufPatems and Trademarks 

1. A FERTILIZER PRODUCT COMPRISING A MATRIX MATERIAL OF DOUGLAS FIR BARK HAVING A SUBSTANTIAL PORTION OF ITS WAX AND CORK REMOVED, AND A WATER-SOLUBLE NUTRIENT FERTILIZER MATERIAL BLENDED INTO SAID MATRIX.
 2. The fertilizer product of claim 1 wherein the Douglas fir bark has about 60 percent of its wax removed.
 3. The fertilizer product of claim 1 wherein the nutrient fertilizer material is urea.
 4. The fertilizer product of claim 1 wherein the nutrient fertilizer material is ammonium nitrate.
 5. The fertilizer product of claim 1 wherein the nutrient fertilizer material is superphosphate.
 6. The fertilizer product of claim 1 wherein the mixture of the matrix material and the nutrient fertilizer material is in pellet form.
 7. The fertilizer product of claim 1 wherein the Douglas fir bark has between about 90 and 95 percent of its cork removed.
 8. THE METHOD OF MAKING A FERTILIZER PRODUCT COMPRISING FIRST EXTRACTING WAX AND THEN REMOVING CORK FROM DOUGLAS FIR BARK TO LEAVE A MATRIX MATERIAL, AND THEN BLENDING A WATER-SOLUBLE NUTRIENT FERTILIZER MATERIAL WITH SAID MATRIX MATERIAL.
 9. The method of claim 8 including pelletizing the blended materials.
 10. The method of claim 8 including applying pressure to the blended materials to heat and combine the materials.
 11. The method of claim 8 wherein the fertilizer material is primarily urea.
 12. The method of claim 8 wherein the fertilizer material is primarily ammonium nitrate.
 13. The method of claim 8 wherein the fertilizer material is primarily superphosphate. 